Mars Doesn’t Have Much of a Magnetosphere, But Here’s a Map

This image is from a scientific visualization of the electric currents around Mars. Electric currents (blue and red arrows) envelop Mars in a nested, double-loop structure that wraps continuously around the planet from its day side to its night side. These current loops distort the solar wind magnetic field (not pictured), which drapes around Mars to create an induced magnetosphere around the planet. In the process, the currents electrically connect Mars’ upper atmosphere and the induced magnetosphere to the solar wind, transferring electric and magnetic energy generated at the boundary of the induced magnetosphere (faint inner paraboloid) and at the solar wind bow shock (faint outer paraboloid). Credits: NASA/Goddard/MAVEN/CU Boulder/SVS/Cindy Starr

Even though Earthling scientists are studying Mars intently, it’s still a mysterious place.

One of the striking things about Mars is all of the evidence, clearly visible on its surface, that it harbored liquid water. Now, all that water is gone, and in fact, liquid water couldn’t survive on the surface of the Red Planet. Not as the planet is now, anyway.

But it could harbour water in the past. What happened?

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InSight has been Sensing Dust Devils Sweep Past its Landing Site

The InSight lander has been on the surface of Mars for about a year, and a half dozen papers were just published outlining some results from the mission. Though InSight’s primary mission is to gather evidence on the interior of Mars—InSight stands for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport—the lander also keeps track of Martian Meteorology. A new paper reports that InSight has found gravity waves, swirling dust devils, and a steady background rumble of infrasound.

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Nothing Says Springtime on Mars Like Explosions of Sand

During winter in the polar regions, a thin layer of carbon dioxide ice covers the surface and then sublimates – turns directly from ice into vapour – with the first light of spring. In the dune fields, this springtime defrosting occurs from the bottom up, trapping gas between the ice and the sand. As the ice cracks, this gas is released violently and carries sand with it, forming the dark patches and streaks observed in this CaSSIS image. ESA/Roscosmos/CaSSIS, CC BY-SA 3.0 IGO

Springtime on Earth can be a riotous affair, as plants come back to life and creatures large and small get ready to mate. Nothing like that happens on Mars, of course. But even on a cold world like Mars, springtime brings changes, though you have to look a little more closely to see them.

Lucky for us, there are spacecraft orbiting Mars with high-resolution cameras, and we can track the onset of Martian springtime through images.

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Where Does Mars’ Methane Go? New Study Provides Possible Answer, with Implications in the Search for Life.

This image illustrates possible ways methane might get into Mars’ atmosphere and also be removed from it: microbes (left) under the surface that release the gas into the atmosphere, weathering of rock (right) and stored methane ice called a clathrate. Ultraviolet light can work on surface materials to produce methane as well as break it apart into other molecules (formaldehyde and methanol) to produce carbon dioxide. Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

For centuries, scientists have speculated about the existence of life on Mars. But it was only within the past 15 years that the search for life (past and present) really began to heat up. It was at this time that methane, an organic molecule that is associated with many forms of life here on Earth (i.e. a “biosignature”) was detected in Mars’ atmosphere.

Since that time, attempts to study Mars’ atmospheric methane have produced varying results. In some cases, methane has been found that was several times its normal concentrations; in others, it was absent. Seeking to answer this mystery, an interdisciplinary team from Aarhus University recently conducted a study where they investigated a possible mechanism for the removal of methane from Mars’ atmosphere.

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Martian Clouds Might Start with Meteor Trails Through the Atmosphere

Mars, as it was observed shortly before opposition in 2016 by the NASA/ESA Hubble Space Telescope. Credit: NASA/ESA/HST

On Earth, clouds form when enough droplets of water condense out of the air. And those droplets require a tiny speck of dust or sea salt, called a condensation nuclei, to form. In Earth’s atmosphere, those tiny specks of dust are lofted high into the atmosphere where they trigger cloud formation. But on Mars?

Mars has something else going on.

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Earth has a Water Cycle. Mars has a Dust Cycle

Comparison images of Mars taken by Hubble (left) and showing a global dust storm that engulfed it (right). Astronomers studying dust storms in the Aonia-Solis-Valles Marineris region over eight years have found a distinct periodicity in their occurrence. Image Credit: NASA

To say there are some myths circulating about Martian dust storms would be an understatement. Mars is known for its globe-encircling dust storms, the likes of which are seen nowhere else. Science fiction writers and Hollywood movies often make the dust storms out to be more dangerous than they really are. In “The Martian,” a powerful dust storm destroys equipment, strands Matt Damon on Mars, and forces him into a brutal struggle for survival.

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The Global Dust Storm that Ended Opportunity Helped Teach us how Mars Lost its Water

Mars in 2001. On the left, no global dust storm. On the right, global dust storm. Image Credit: By Jim Secosky picked out this NASA image NASA/JPL/MSSS - https://photojournal.jpl.nasa.gov/figures/PIA03170_fig1.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=65809875
Mars in 2001. On the left, no global dust storm. On the right, global dust storm. Image Credit: By Jim Secosky picked out this NASA image NASA/JPL/MSSS - https://photojournal.jpl.nasa.gov/figures/PIA03170_fig1.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=65809875

The enduring, and maybe endearing, mystery around Mars is what happened to its water? We can say with near-certainty now, thanks to the squad of Mars rovers and orbiters, that Mars was once much wetter. In fact that planet may have had an ocean that covered a third of the surface. But what happened to it all?

As it turns out, the global dust storms that envelop Mars, and in particular the most recent one that felled the Opportunity rover, may offer an explanation.

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Rivers on Mars Flowed for More Than a Billion Years

A photo of a preserved river channel on Mars. The color is overlaid to show elevation, with blue being low and yellow being high elevation. Image Credit: NASA/JPL/Univ. Arizona/UChicago
A photo of a preserved river channel on Mars. The color is overlaid to show elevation, with blue being low and yellow being high elevation. Image Credit: NASA/JPL/Univ. Arizona/UChicago

The ancient climate of Mars is a mystery to scientists. Even with all we’ve learned about Mars, it’s still difficult to explain how lakes and rivers existed. A new study shows that Martian rivers were swollen with runoff and that they flowed far later into the planet’s history than previously thought.

The question is, how did the Martian climate create these conditions?

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